Implement web speech synthesis.

chrome/browser/speech/extension_api/tts_engine_extension_api.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_SPEECH_EXTENSION_API_TTS_ENGINE_EXTENSION_API_H_
 #define CHROME_BROWSER_SPEECH_EXTENSION_API_TTS_ENGINE_EXTENSION_API_H_
 
+#include <vector>
+
 #include "base/memory/singleton.h"
 #include "chrome/browser/extensions/extension_function.h"
+#include "chrome/browser/speech/tts_controller.h"
 
 class Utterance;
 
 namespace base {
 class ListValue;
 }
 
 namespace extensions {
 class Extension;
 }
 
 namespace tts_engine_events {
 extern const char kOnSpeak[];
 extern const char kOnStop[];
 }
 
 // Return a list of all available voices registered by extensions.
-void GetExtensionVoices(Profile* profile, base::ListValue* result_voices);
+void GetExtensionVoices(Profile* profile, std::vector<VoiceData>* out_voices);
 
 // Find the first extension with a tts_voices in its
 // manifest that matches the speech parameters of this utterance.
 // If found, store a pointer to the extension in |matching_extension| and
 // the index of the voice within the extension in |voice_index| and
 // return true.
 bool GetMatchingExtensionVoice(Utterance* utterance,
                                const extensions::Extension** matching_extension,
                                size_t* voice_index);
 
@@ skipping 10 matching lines @@
 // Hidden/internal extension function used to allow TTS engine extensions
 // to send events back to the client that's calling tts.speak().
 class ExtensionTtsEngineSendTtsEventFunction : public SyncExtensionFunction {
  private:
   virtual ~ExtensionTtsEngineSendTtsEventFunction() {}
   virtual bool RunImpl() OVERRIDE;
   DECLARE_EXTENSION_FUNCTION("ttsEngine.sendTtsEvent", TTSENGINE_SENDTTSEVENT)
 };
 
 #endif  // CHROME_BROWSER_SPEECH_EXTENSION_API_TTS_ENGINE_EXTENSION_API_H_